An Electronic Control Unit (ECU) is used in many different types of vehicles to provide control over the operation of various components. The ECU is used to control various actuators which are part of an engine to optimize the operation of the engine. The ECU controls air-fuel mixture, ignition timing, idle speed, and in some more advanced versions of an ECU, variable valve timing, transient fueling, maximum RPM, and the like, are also controlled by the ECU.
The ECU is often required to function in a harsh environment, where the ECU may be exposed to different temperatures, as well as moisture. The ECU includes a cover which is part of a casing, and after assembly, the casing is tested for leaks to make sure that no moisture or debris is able to enter into the casing and damage any internal components. One type of approach to test the ECU for leaks is to force pressurized air into an aperture formed as part of the cover, referred to as a “leak test aperture,” and determine if any air leaks out of the casing. Once the test is complete, a seal is deposited into the aperture.
However, current seals used in leak test apertures do not adequately provide assurance that the leak test aperture is sealed. Some of these seals do not provide an adequate sealing function due to die casting surface irregularities in the leak test aperture. Also, the location of the seal in the leak test aperture may not always be known once the ECU is assembled, making it difficult to determine whether the leak test aperture is in fact sealed.
Accordingly, there exists a need for an improved sealing of a leak test aperture once the assembly of the ECU is completed.